Aerial manlift devices commonly take the form of an interconnected series of one or more boom members supported on a vehicular platform. The boom members may be adjusted relative to one another, for example by a telescoping action, to various heights and angles relative to the vehicular platform to achieve access to a repair site. Alternatively, a single boom section may be raised or lowered to orient the outer end of the boom to the desired height and directional orientation.
A common attachment to an aerial manlift device is a walled platform comprising a worker's bucket which is affixed, for example by a support bracket, to the outermost end of the boom. An example of an arrangement wherein a worker's bucket is connected to the boom by a mounting bracket is shown in U.S. Pat. No. 3,295,633.
It is desirable in an aerial manlift arrangement including a worker's bucket to be able to pivotally release the worker's bucket to allow the bucket to fall from its upright position, under the influence of gravity, to a horizontal position without completely detaching the bucket from the mounting bracket structure. This feature is useful, for example, to empty water or debris which may have accumulated in the bucket, or more importantly, to assist in removing an injured worker in the event of an accident or an emergency. In prior art structures having a bucket release feature of this type, the structure utilizes a removable detent pin, whereby the bucket is held in upright position by the pin and is permitted to pivot to a horizontal orientation upon removal of the pin. An example of this type of bucket support arrangement is disclosed in U.S. Pat. No. 4,334,594. A significant drawback of a structure utilizing a removable detent pin is that any load or weight inside the worker's bucket tends to make the pin difficult to remove, and renders operation of the bucket release cumbersome when any substantial weight is present within the bucket.